A conventional music box, as indicated in U.S. Pat. No. 4,557,173, includes a KOUBAKO (a spring storage box) storing therein the spring, a rotary drum driven in one direction in accordance with release of stored force of the spring, a sound vibration valve (hereinafter referred to as only vibration plate) sounding while being played with engaging pin provided on the surface of the rotary drum, a governor mechanism for rotating the rotary drum with fixed speed, gear train for coupling the governor mechanism and the spring. Such functional members described-above are mounted directly on a casting metallic frame made of zinc die casting or iron or so forth. Further, a member which includes a part of supporting section of gear train and one side of bearing section that supports a governor rotating body, which member leads a braking section of the governor mechanism from the spring storage box, is formed with synthetic resin in a body.
However, since the bearing section which supports rotary members such as the governor rotating body and respective gears and so forth is integrated with the frame concentrically, shape of the frame becomes complicated, so processing is difficult. Further, a casting metal such as a zinc die casting and so forth to be material of the frame has large coefficient of friction. Accordingly, when a rotary member which rotates in high speed is supported directly on the frame, rotation transfer efficiency of the gears deteriorates, thus the spring with small stored capacity of driving force becomes disadvantage.
So, it is an object of the present invention to provide a music box device in which a bearing section of a rotary member is formed with synthetic resin separately from the frame so as to improve a rotation transfer efficiency of a gear, and in which a spring, a gear train, and a governor mechanism are configured as one body unit to facilitate installation for the frame.